The Hobbit: The Desolation of Smaug's recently leaked trailer rocked the whole world with its epic awesomeness, but two girls were more more than most!!

These self-professed "Happy Hobbits" geeked out so hard while watching the teaser, their reaction (above) went viral!!

In fact, the ladies' love for the clip was so super-passionate that director Peter Jackson let Hobbit stars Orlando Bloom, Evangeline Lilly, and Lee Pace watch the reaction vid while still in costume!!!

AND THEY LOVED IT!!

Ch-ch-check out the cast reacting to the uber-fans who freaked out over the trailer…AFTER THE JUMP!!!

Our favorite Twi-Hard of all-time is EASILY Nutty Madam, who has kept a relatively low-profile since spontaneously combusting into thousands of vampire sparkles after the concluding chapter of The Twilight Saga, Breaking Dawn - Part 2premiered back in November.

But she re-emerged this week on YouTube to share with the world what must have singlehandedly been the most defining moment of her entire LIFE!

Zayn previewed the duet by posting a black and white pic of himself with Swifty on his Instagram -- but hey, she is bestiez with his girlfriend Gigi Hadid, so it wouldn't be unusual that they hang out... But collab?!